Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 9th April)

Features of the Forecast (tl;dr)

• Flukey S swell Fri with light winds
• Small, fun E’ly swells starting to show this weekend
• Flukey long period S swells in the water this weekend favouring S swell magnets
• Slow building E swells early next week with light winds
• Much more significant E swell now a possibility as tropical depression drifts down into wide open E swell window- still low confidence in specifics so check back Fri for the latest updates

Recap

S swell showed strongly yesterday, building into the 3-5ft range at S facing beaches in the a’noon, bigger on the Hunter. Conditions were OK with a light offshore flow trending to light onshores. Similar conditions this morning with generally light winds although they are swirling around. Surface conditions are basically clean with S swells still in the 4ft range and expected to slowly ease back through the day. 

Still plenty of energy at S facing beaches this morning under light winds

This week (Apr 9-11)

High pressure is moving into the Tasman, strengthening as it drifts towards New Zealand, where it is expected to become a dominant “flat topped” feature, reinforced by subsequent high pressure moving into the Tasman. We’ll see a long E’ly fetch develop through the South Pacific slot through the end of this week, enhanced by a trough of low pressure near New Caledonia which is attached to a still active monsoon trough. This will be the main swell source into the medium term. The storm track under the continent is active but fetches are mostly zonal so we’ll only see minor, flukey long period S swell wrap. That storm track is further suppressed into next week by the dominant downstream blocking high pressure pattern.

In the short run, we’re only expecting a small blend of leftover S-S/SE swells and some flukey long period stuff, topping out in the 2ft range with a few magnets offering an occ. 3ft set. Conditions should be nice for the early with light W-NW winds, tending to light/mod N-NE seabreezes.

A flukey S swell for Fri generated by a small low that traversed the polar shelf, south-west of Tassie yesterday offering an inconsistent occ. 2-3ft wave for S facing beaches and minor E/NE swell coming off the high at similar levels. Light winds again, so worth a look at S swell magnets but keep expectations pegged fairly low.

This weekend (Apr 12-13)

Not much change for the weekend f/cast as New Zealand is straddled by two large high pressure cells with the Northern Tasman to Coral Seas and extending out into the South Pacific filled with SE-E’ly winds. Local winds along the temperate NSW coast should stay light through Sat, with morning offshores and light a’noon SE-E breezes. Similar light winds for Sun with a more N-NE bias through the day.

The weekend will start small but slowly by degrees we’ll see swells start to fill in from the E/NE. 

Expect 2ft surf through Sat, with a slow incremental increase on Sun into the 2-3ft range. Also in the mix will be some small long period S swell wrap offering up some 2 occ. 3ft sets at S swell magnets. Nothing amazing but with light winds there should be a few fun waves to be had. 

Next week (Apr 14 onwards)

The trend will be slowly, slowly up next week as we move into the Easter week. Another high pressure moves into the Tasman early next week to reinforce the pattern, with a NE movement holding light winds across temperate NSW and a much stronger ridge into the sub-tropics. Fairly typical for autumn.

Model divergence through the week becomes profound in the second half of the week with GFS suggesting a large tropical depression drifting down from a position south of New Caledonia right through the wide open E swell window (see below). Under this scenario we’d see the early part of the week with small, fun E swells, becoming much sizier from Thurs into the weekend. Basically an east coast wide swell event from the E.

Caution is required because the much more conservative ECMWF take positions the low north of the North Island where it slips behind the North island as it develops. We’ll still see the fun first half of the week and potentially a nice pulse from the E but not to the same duration or size as the GFS resolution. 

We’ll pay close attention these model developments and report back Fri, hopefully with news of an extended sizeable swell event from the E.

Seeya then!